feat: execute durable client commands through supervisor

internal/client/agent/handshake.go

@@ -77,16 +77,27 @@ func Reconcile(ctx context.Context, transport Transport, session Session, snapsh
 	if err := transport.Write(ctx, encoded); err != nil {
 		return nil, err
 	}
-	received, err := transport.Read(ctx)
-	if err != nil {
-		return nil, err
+	for {
+		received, err := transport.Read(ctx)
+		if err != nil {
+			return nil, err
+		}
+		result, err := agentproto.DecodeEnvelope(received, limits, rvboxv1.Platform_PLATFORM_WINDOWS)
+		if err != nil {
+			return nil, fmt.Errorf("decode reconciliation response: %w", err)
+		}
+		if result.GetSessionId() != session.ID || result.GetSessionGeneration() != session.Generation {
+			return nil, ErrProtocolHandshake
+		}
+		if result.GetReconcileRequest() != nil {
+			// The request may have been queued before the client's snapshot write
+			// reached the server. The snapshot is already on the wire; consume the
+			// advisory target frame and continue waiting for the durable result.
+			continue
+		}
+		if result.GetReconcileResult() == nil {
+			return nil, ErrProtocolHandshake
+		}
+		return proto.Clone(result.GetReconcileResult()).(*rvboxv1.ReconcileResult), nil
 	}
-	result, err := agentproto.DecodeEnvelope(received, limits, rvboxv1.Platform_PLATFORM_WINDOWS)
-	if err != nil {
-		return nil, fmt.Errorf("decode ReconcileResult: %w", err)
-	}
-	if result.GetSessionId() != session.ID || result.GetSessionGeneration() != session.Generation || result.GetReconcileResult() == nil {
-		return nil, ErrProtocolHandshake
-	}
-	return proto.Clone(result.GetReconcileResult()).(*rvboxv1.ReconcileResult), nil
 }